Dynamically opening a file for play would require more isolation of globals. We did something in this direction, but it's far for complete. Think about the VM... that will drive the operations based on version of the topmost movie. Classes will be initizalized
based on that version too (think extensions) !

In order for this to work we'd need to pass around a reference
to a "run context" object to a lot of functions, or do you see other options ?

I just checked in a variation of pathc #5640, which partially implements this task. The Menu items are there and the callbacks get called, but the support in the Player class isn't finished sufficiently to open and play a movie from a menu item just yet.

It would be very useful for the standalone player to have an "open file" dialog box that's accessible from the right click menu, or maybe we should add a top menu bar. This would enable Gnash to work better on a PDA, where one doesn't always have access to a command line to specify what movie Gnash should play.